Sock

ABSTRACT

A sock 1 according to the invention is provided with an outer low-elasticity portion  7  having a length extending from a region near a base part of a fifth toe to a region near an outer malleolus part  3   a  via an outer face, and a width extending from a region near a first toe side of a fourth toe on an instep side to a region near a first toe side of the fifth toe on a volar side, an upper taping low-elasticity portion  8  formed in a direction substantially toward an inner malleolus part  3   b  side from a portion between the ankle and the region near the first toe side of the fourth toe in the outer low-elasticity portion  7  on the instep side, and an upper ankle low-elasticity portion  10  formed in the upper ankle part in a circumferential direction.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a sock capable of sufficiently reducing the load on the foot and improving movement capability by everting the ankle.

Description of the Related Art

A sock that everts the ankle is conventionally known. In a sock of this kind, a band-shaped first low-elasticity region 101 that is less elastic than other regions is provided in an instep part. The first low-elasticity region 101 includes at least the ankle flexion portion 101 d, and extends on the lower end side of the ankle flexion portion 101 d to the base part of the toe, with the center line (thereof) relative to the width in a course direction gradually shifting to the fifth toe side. A lower end portion 101 b is located in an area from the base part of the third toe to the base part of the fifth toe (see FIG. 3). A side portion 101 c on the fifth toe side close to the lower end of the first low-elasticity region extends to the sole side so as to wrap around the fifth metatarsal bone. A force (P) can be exerted in a direction pulling the lower end portion 101 b located in the area from the base part of the third toe to the base part of the fifth toe toward the ankle flexion portion 101 d along the first low-elasticity region 101, and a force pulling up the entire fifth toe side of the foot can be obtained by hooking the side portion 101 c near the fifth toe side in a vicinity of the lower end of the first low-elasticity region 101 around the fifth metatarsal bone (see FIG. 4). Thus, the first low-elasticity region 101 applies a force that moderately lifts up the foot from the fifth toe side in a direction toward the ankle flexion portion, such that a resistive force acts against twisting in a direction inverting the ankle. Therefore, inversion sprains can be effectively prevented (e.g. JP 2009-275300A).

However, because the conventional sock, which effectively prevents inversion sprains by applying a force pulling up the entire fifth toe side of the foot, lifts up the foot from the fifth toe side in the direction toward the ankle flexion portion, this sock cannot sufficiently turn the entire foot in the everting direction. Therefore, during walking, the outside of the bottom of the foot lands before the inside after the heel lands, and the conventional sock does not allow the inside and outside of the foot to land on the ground substantially simultaneously. Since the conventional sock thus does not allow the inside and outside of the bottom of the foot to land on the ground substantially simultaneously during walking, a problem arises in that the load on the foot cannot be reduced sufficiently.

Moreover, during running, the foot lands on the ground from the region near the toe tip part of the bottom of the foot. However, the conventional sock also does not allow the inside and outside of the region near the toe tip part of the bottom of the foot to land on the ground substantially simultaneously during running. Thus, during running, especially during short-distance running, given that the sock does not allow the inside and outside of the toe tip part of the bottom of the foot to land on the ground substantially simultaneously, a problem arises in that time is required for the temporal difference that occurs between when the inside and the outside of the region near the toe tip part of the bottom of the foot land on the ground, and the person who wears this sock cannot do a fast time for that reason. Furthermore, especially during short-distance running, if the outside of the foot lands and then the inside of the foot lands, the running direction points outward of the foot during running, and therefore, a problem also arises in that the person who wears the sock unconsciously runs in a direction that slightly deviates from a straight direction, and cannot do a fast time for that reason.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a sock capable of sufficiently reducing the load on the foot and improving movement capability.

A first aspect of the invention is a sock having an annular body portion constituting a region from an opening into which a foot is inserted to substantially a malleolus part, and the foot portion formed integrally with the body portion and constituting a region substantially from an end of the malleolus part to a toe tip part, and provided with a low-elasticity portion that is less elastic than another part, the sock including; an outer low-elasticity portion having a length extending from a region near a base part of a fifth toe to a region near an outer malleolus part via an outside face, and a width extending from a region near a first toe side of a fourth toe on an instep side to a region near a first toe side of the fifth toe on a volar side, the outer low-elasticity portion being less elastic than another part; an upper taping low-elasticity portion formed in a direction substantially toward an inner malleolus part side from a portion between an ankle and a base part of the fourth toe in the outer low-elasticity portion on the instep side, the upper taping low-elasticity portion being less elastic than another part; and an upper ankle low-elasticity portion formed in a circumferential direction in an upper ankle part and being less elastic than another part, wherein a shape of the sock from the toe tip part of the foot portion to the opening of the body portion is formed in substantially an arcuate shape such that an outer side of the sock is shorter than an inner side of the sock.

According to the present invention, the shape of the sock from the toe tip part of the foot portion to the opening of the body portion is formed in substantially an arcuate shape, and the instep side of the outer low-elasticity portion has a width extending to the region near the first toe side of the fourth toe that is larger than the lateral width of the volar side of the outer low-elasticity portion. Therefore, the entire foot on the outer side of the foot portion extending from the region near the base part of the fifth toe to the region near the outer malleolus part receives a force in an everting direction while being tightened. In this state, the entire foot on the outer side of the foot portion is pulled in a direction substantially toward the inner malleolus part from a portion between the ankle and the region near the first toe side of the fourth toe in the outer low-elasticity portion on the instep side by the upper taping low-elasticity portion. Thus, by the entire foot on the outer side of the foot portion being pulled in the direction substantially toward the inner malleolus part in a state where the entire foot on the outer side of the foot portion is receiving the force in the everting direction while being tightened, when a person walks with this sock on, the entire bottom of the foot will be made substantially parallel with the ground, and when the foot lands, the sock allows the inside and outside of the bottom of the foot to land on the ground substantially simultaneously. Thus, the load on the foot can be sufficiently reduced. In addition, the person who wears the sock can run straight, and power can be transmitted efficiently, achieving an improvement in movement capability.

A second aspect of the invention is the sock in the first aspect of the invention further including a lower taping low-elasticity portion formed in a direction substantially toward the inner malleolus part side from a region near a heel part side between a heel part and the base part of the fifth toe in the outer low-elasticity portion on a sole side, the lower taping low-elasticity portion being less elastic than another part.

According to the present invention, the lower taping low-elasticity portion is formed in the direction substantially toward the inner malleolus part side from the region near the heel part side between the heel part and the base part of the fifth toe in the outer low-elasticity portion on the sole side. Therefore, the lower taping low-elasticity portion can strongly pull the entire foot on the outer side of the foot portion in the direction substantially toward the inner malleolus part in cooperation with the upper taping low-elasticity portion. Thus, when a person walks with this sock on, the entire bottom of the foot will be made substantially parallel with the ground stably. When the foot lands, the sock allows the inside and outside of the bottom of the foot to stably land on the ground substantially simultaneously.

A third aspect of the invention is the sock in the first or second aspect of the invention, wherein the upper ankle low-elasticity portion is formed over substantially the entire circumference of the upper ankle part, and a part of the upper ankle low-elasticity portion in the circumferential direction is formed to be more elastic than a remaining part of the upper ankle low-elasticity portion.

According to the invention, the upper ankle low-elasticity portion is formed over substantially the entire circumference in the upper ankle part. Therefore, the sock can be firmly fixed at the ankle position, and shifting of the sock can be suppressed. As a result, an effect of making the entire bottom of the foot substantially parallel with the ground in a state of wearing the sock can be stably achieved. Furthermore, since a part in the circumferential direction the upper ankle low-elasticity portion is formed so as to be more elastic than the remaining part of the upper ankle low-elasticity extension portion, the upper ankle part can be easily widen in the circumferential direction. As a result, the sock can be easily put on and taken off, and it is also possible to avoid an oppressive sensation when wearing the sock and prevent blood circulation from deteriorating.

With the sock according to the present invention, by the entire foot on the outer side of the foot portion being pulled in the direction substantially toward the inner malleolus part in a state where the entire foot on the outer side of the foot portion is receiving the force in the everting direction, when a person walks with this sock on, the entire bottom of the foot is made substantially parallel with the ground. When the foot lands, the sock allows the inside and outside of the bottom of the foot to land on the ground substantially simultaneously. Thus, the load on the foot can be sufficiently reduced. In addition, the person who wears the sock can run straight, and power can be transmitted efficiently, achieving an improvement in movement capability.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of socks according to an embodiment of the present invention.

FIG. 2A is a front view of the socks. FIG. 2B is a back view of the socks.

FIG. 3 shows an instep part side of a conventional sock.

FIG. 4 is a perspective view of the conventional sock.

DESCRIPTION OF THE EMBODIMENTS

A first embodiment of a sock according to the present invention will be hereinafter described with reference to the drawings. Here, FIG. 1 is a front perspective view of socks according to an embodiment of the present invention, FIG. 2A is a front view of the socks, and FIG. 2B is a back view of the socks.

As shown in FIG. 1, socks 1, namely a right sock 1R and a left sock 1L have a left-right symmetrical shape. Each sock 1 is formed with an annular body portion 4 that constitutes an area from an opening 2 into which the foot is inserted to substantially a malleolus part 3, and the foot portion 6 that is formed integrally with the body portion 4 and constitutes an area from an end of the malleolus part 3 to a toe tip part 5. The sock 1 is provided with low-elasticity portions that are less elastic than the other parts. Here, the malleolus part 3 refers to a portion around the malleolus, and is a concept that also includes a part slightly above the malleolus and a part slightly below the malleolus. Note that although short socks 1 are used in the description of this embodiment, the present invention is not limited thereto, and other kinds of socks such as high socks may be employed as long as the socks each have the body portion 4 and the foot portion 6. The low-elasticity portion that is less elastic than the other parts according to this embodiment will be described below in detail.

As the low-elasticity portions that are less elastic than the other parts, each sock 1 is provided with an outer low-elasticity portion 7, an upper taping low-elasticity portion 8, a lower taping low-elasticity portion 9, an upper ankle low-elasticity portion 10, and the like (see FIGS. 1 and 2).

The outer low-elasticity portion 7 has a length extending from a region near the base part of a fifth toe to a region near an outer malleolus part 3 a via an outer face, and a width extending from a region near a first toe side of a fourth toe on the instep side to a region near a first toe side of the fifth toe on the volar side. When the sock 1 is knitted, in this outer low-elasticity portion 7, a tuck stitch is used in which a plurality of lateral course yarns are bundled together to make a stitch. FTY, which is a highly elastic material, is used as the back-side thread. Furthermore, rubber thread is knitted in, thereby reducing the elasticity. Thus, a highly elastic material is used, and the number of stitches in a longitudinal direction is reduced to closely pack the stiches together in the longitudinal direction by means of the tuck stitch. As a result of the reduction in the number of stitches, the outer low-elasticity portion 7 is formed to be less elastic than the other parts. Here, a “tuck stitch” is a way of knitting that involves forming a fabric by making stitches together when knitting the next course without making a certain stitch. Since the stitch is not allowed to come out of a knitting needle, the stitch is held together with the previous stitch of a hook or a stem of the knitting needle, and the knitting yarn is withdrawn under a plurality of stitches simultaneously to make a new stitch when forming a stitch with the next feed yarn, for example. Note that, in this embodiment, the elasticity of the outer low-elasticity portion 7 is reduced by forming the outer low-elasticity portion 7 using a tuck stitch and knitting FTY and rubber thread therein. However, the invention is not limited thereto, and FTY and rubber thread may not be knitted therein.

In the outer low-elasticity portion 7, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under four stitches simultaneously to make a new stitch. Thus, in the outer low-elasticity portion 7, the number of stitches is reduced by the tuck stitch. Therefore, the space of the stitches is reduced, and resistance to stretching is exerted against a stretch as a result of the reduction in the number of stitches that can be stretched. The outer low-elasticity portion 7 is thereby formed to be less elastic than the other parts. Here, “being less elastic than the other parts” means being less elastic than a part having a predetermined elasticity. In this embodiment, even though an elasticity process such as a tuck stitch is performed, when a stitch is formed with the next feed yarn, the knitting yarn is withdrawn under two stitches simultaneously to make a new stitch, thereby reducing the elasticity compared with parts that are slightly more elastic.

Thus, the outer low-elasticity portion 7, whose length extends from the region near the base part of the fifth toe of the sock 1 to the region near the outer malleolus part 3 a via the outer face, and whose width extends from the region near the first toe side of the fourth toe on the instep side to the region near the first toe side of the fifth toe on the volar side, is formed to be less elastic than the other parts. Therefore, the outer part of the sock 1 contracts in the longitudinal direction, and the shape of the sock 1 from the toe tip part 5 of the foot portion 6 to the opening 2 of the body portion 4 is shorter on the outer side than on the inner side, thus resulting in the sock 1 being formed in substantially an arcuate shape. Here, “being formed in substantially an arcuate shape” is a concept that includes being formed in substantially an inverted arcuate shape. Note that, although the sock 1 is formed in substantially an arcuate shape in this embodiment, the present invention is not limited thereto. The sock 1 may be formed in substantially a Japanese character “Ku” shape, a banana-like shape or a boomerang-like shape that is very similar to being formed in substantially an arcuate shape and is a smoothly outwardly curved shape, or may be formed in substantially a slightly inwardly curved shape. The sock 1 from the toe tip part 5 of the foot portion 5 to the opening 2 of the body portion 4 is formed in substantially an arcuate shape, and the lateral width of the outer low-elasticity portion 7 on the instep side is larger than on the volar side and expands to the region near the first toe side of the fourth toe. Therefore, when this sock 1 is worn, the foot receives a force in a direction everting the entire foot on the outer side of the foot portion 6 extending from the region near the base part of the fifth toe to the region near the outer malleolus part 3a.

The upper taping low-elasticity portion 8 is formed in a direction substantially toward an inner malleolus part 3 b from a portion between the ankle and the base part of the fourth toe in the outer low-elasticity portion 7 on the instep side of the sock 1. That is to say, a side of the upper taping low-elasticity portion 8 on the toe tip part 5 side is formed at least in a direction substantially to the inner malleolus part 3 b side from a portion between the base part of the fourth toe and the ankle. Here, the “direction toward the inner malleolus part 3 b side” may slightly diverge from the direction toward the inner malleolus part 3 b as long as the direction points toward the inner malleolus part 3 b side. Note that the “direction substantially toward the inner malleolus part 3 b side” mentioned below is also used to have the same meaning.

In the upper taping low-elasticity portion 8, similar to the above-described outer low-elasticity portion 7, a tuck stitch is used, FTY, which is a highly elastic material, is used as the back-side thread, and rubber thread is knitted in, thereby reducing the elasticity. Note that the upper taping low-elasticity portion 8 has the same elasticity as that of the outer low-elasticity portion 7. Specifically, regarding tuck stitch in the upper taping low-elasticity portion 8 as well, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under four stitches simultaneously to make a new stitch. The entire foot on the outer side of the foot portion 6 is pulled in a direction substantially toward the inner malleolus part 3 b from a portion between the ankle and the region near the first toe side of the fourth toe in the outer low-elasticity portion 7 on the instep side by the upper taping low-elasticity portion 8. Note that, in this embodiment, the elasticity of the upper taping low-elasticity portion 8 is reduced by forming the upper taping low-elasticity portion 8 using a tuck stitch and knitting FTY and rubber thread therein. However, the invention is not limited thereto, and FTY and rubber thread may not be knitted therein.

Thus, in a state where a force is exerted in a direction everting the entire foot on the outer side of the foot portion 6 from the region near the base part of the fifth toe to the region near the outer malleolus part 3 a by the outer low-elasticity portion 7, the entire foot on the outer side of the foot portion 6 is pulled in the direction substantially toward the inner malleolus part 3 b by the upper taping low-elasticity portion 8.

As described above, as a result of the entire foot on the outer side of the foot portion 6 being pulled in the direction substantially toward the inner malleolus part 3 b in a state where a force in the direction everting the entire foot on the outer side of the foot portion 6 is exerted, when a person walks with the sock 1 on, the entire bottom of the foot is made substantially parallel with the ground. When the foot lands, the inside and outside of the bottom of the foot can be caused to land on the ground substantially simultaneously. Thus, the load on the foot can be sufficiently reduced. In addition, the person who wears the sock 1 can run straight, and power can be transmitted efficiently, achieving an improvement in movement capability. Furthermore, the best performance of this effect can be exhibited by producing the sock 1 in 1.0 centimeter increments and wearing a sock 1 that is generally the same size as the size of the foot.

The lower taping low-elasticity portion 9 is formed in a direction substantially toward the inner malleolus part 3 b side from a region near the heel part side of a portion between the heel part and the base part of the fifth toe in the outer low-elasticity portion 7 on the sole side of the sock 1. That is to say, a side of the lower taping low-elasticity portion 9 on the toe tip part 5 side is formed at least in a direction from the region near the heel part side of the portion between the base part of the fifth toe and the ankle substantially to the inner malleolus part 3 b side.

In the lower taping low-elasticity portion 9 as well, similar to the above-described upper taping low-elasticity portion 8, a tuck stitch is used, FTY, which is a highly elastic material, is used as the back-side thread, and rubber thread is knitted in, thereby reducing the elasticity. Here, the lower taping low-elasticity portion 9 has the same elasticity as that of the upper taping low-elasticity portion 8. Specifically, regarding the tuck stitch in the lower taping low-elasticity portion 9 as well, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under four stitches simultaneously to make a new stitch. Note that, in this embodiment, the elasticity of the lower taping low-elasticity portion 9 is reduced by forming the lower taping low-elasticity portion 9 using a tuck stitch and knitting FTY and rubber thread therein. However, the invention is not limited thereto, and FTY and rubber thread may not be knitted therein.

A lower taping low-elasticity extension portion 11 is formed in an extending direction of the lower taping low-elasticity portion 9. In the lower taping low-elasticity extension portion 11 as well, similar to the lower taping low-elasticity portion 9, a tuck stitch is used, FTY, which is a highly elastic material, is used as the back-side thread, and rubber thread is knitted in, thereby reducing the elasticity. Here, the lower taping low-elasticity extension portion 11 is slightly more elastic than the lower taping low-elasticity portion 9. Specifically, regarding the tuck stitch in the lower taping low-elasticity extension portion 11, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under three stitches simultaneously to make a new stitch. Note that, in this embodiment, the elasticity of the lower taping low-elasticity extension portion 11 is reduced by forming the lower taping low-elasticity extension portion 11 using a tuck stitch and knitting FTY and rubber thread therein. However, the invention is not limited thereto, and FTY and rubber thread may not be knitted therein.

In this manner, the lower taping low-elasticity portion 9 is formed in the direction substantially toward the inner malleolus part 3 b from the region near the heel part side of the portion between the heel part and the base part of the fifth toe in the outer low-elasticity portion 7 on the sole side. Therefore, the lower taping low-elasticity portion 9 can strongly pull the entire foot on the outer side of the foot portion 6 in the direction substantially toward the inner malleolus part 3 b in cooperation with the upper taping low-elasticity portion 8. Thus, when a person walks with this sock 1 on, the entire bottom of the foot is made substantially parallel with the ground stably. When the foot lands, the inside and outside of the bottom of the foot can be caused to stably land on the ground substantially simultaneously.

Furthermore, an upper ankle low-elasticity portion 10 is formed in the upper ankle part of the sock 1 in a circumferential direction. This upper ankle low-elasticity portion 10 need only be formed in the upper ankle part in the circumferential direction, and may not necessarily be formed around the entire circumference of the ankle. In the upper ankle low-elasticity portion 10 as well, similar to the above-described upper taping low-elasticity portion 8, a tuck stitch is used, FTY, which is a highly elastic material, is used as the back-side thread, and rubber thread is knitted in, thereby reducing the elasticity. Here, the outside of the upper ankle low-elasticity portion 10 is less elastic than on the inside of the upper ankle low-elasticity portion 10. Specifically, in tuck stitch on the outside of the upper ankle low-elasticity portion 10, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under four stitches simultaneously to make a new stitch. In tuck stitch on the inside of the upper ankle low-elasticity portion 10, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under three stitches simultaneously to make a new stitch. Note that all tuck stitch of the upper ankle low-elasticity portion 10 may be performed by withdrawing, when forming a stitch with the next feed yarn, the knitting yarn so as to simultaneously pass under four stitches to make a new stitch. Also, in this embodiment, the elasticity of the upper ankle low-elasticity portion 10 is reduced by forming the upper ankle low-elasticity portion 10 using a tuck stitch and knitting FTY and rubber thread therein. However, the invention is not limited thereto, and FTY and rubber thread may not be knitted therein. By thus making the elasticity on the outside of the upper ankle low-elasticity portion 10 smaller than the elasticity on the inside of the upper ankle low-elasticity portion 10, the shape of the sock 1 can be formed to be more substantially arcuate shaped.

An upper ankle low-elasticity extension portion 12, which is more elastic than the other parts, is formed in a part in the ankle circumferential direction of the upper ankle low-elasticity portion 10. Note that, in this embodiment, the upper ankle low-elasticity portion 10 and the outer low-elasticity portion 7 are formed in communication with each other. However, the present invention is not limited thereto, and the upper ankle low-elasticity portion 10 and the outer low-elasticity portion 7 may be separated from each other so as to be not in communication with each other. In the upper ankle low-elasticity extension portion 12 as well, similar to the above-described upper ankle low-elasticity portion 10, a tuck stitch is used, FTY, which is a highly elastic material, is used as the back-side thread, and rubber thread is knitted in, thereby reducing the elasticity. Here, the upper ankle low-elasticity extension portion 12 is slightly more elastic than the upper ankle low-elasticity portion 10. Specifically, regarding the tuck stitch in the upper ankle low-elasticity extension portion 12, when a stitch is formed with the next feed yarn, a knitting yarn is withdrawn under two stitches simultaneously to make a new stitch. Also, in this embodiment, the elasticity of the upper ankle low-elasticity extension portion 12 is reduced by forming the upper ankle low-elasticity extension portion 12 using a tuck stitch and knitting FTY and rubber thread therein. However, the invention is not limited thereto, and FTY and rubber thread may not be knitted therein.

Since the upper ankle low-elasticity portion 10 is thus formed over the circumferential direction in the upper ankle, the sock 1 can be firmly fixed at the ankle position, and shifting of the sock 1 can be suppressed. As a result, an effect of making the entire bottom of the foot substantially parallel with the ground in a state of wearing the sock 1 can be stably achieved. Furthermore, since the upper ankle low-elasticity extension portion 12 that is more elastic than the other parts of the upper ankle low-elasticity portion 10 is formed in a part in the circumferential direction, the upper ankle part can be easily widened in the circumferential direction. As a result, the sock 1 can be easily put on and taken off, and it is also possible to avoid an oppressive sensation when wearing the sock 1 and prevent blood circulation from deteriorating.

As described above, as a result of using the sock 1 according to this embodiment, the entire bottom of the foot is made substantially parallel with the ground when a person walks with this sock 1 on, by the entire foot on the outer side of the foot portion 6 being pulled in the direction substantially toward the inner malleolus part 3 b in a state where a force in the everting direction is exerted on the entire foot on the outer side of the foot portion 6. When the foot lands, the inside and outside of the bottom of the foot can be caused to land on the ground substantially simultaneously. Thus, the load on the foot can be sufficiently reduced. In addition, the person who wears the sock 1 can run straight, and power can be transmitted efficiently, achieving an improvement in movement capability.

The above-disclosed embodiment is an example in all respects, and should be considered to be not restrictive. The scope of the present invention is defined not by the above description but by the patent claims, and is intended to encompass all modifications within the meaning and the scope equivalent to the patent claims. 

What is claimed is:
 1. A sock having an annular body portion constituting a region from an opening into which a foot is inserted to substantially a malleolus part, and the foot portion formed integrally with the body portion and constituting a region substantially from an end of the malleolus part to a toe tip part, and provided with a low-elasticity portion that is less elastic than another part, the sock comprising: an outer low-elasticity portion having a length extending from a region near a base part of a fifth toe to a region near an outer malleolus part via an outside face, and a width extending from a region near a first toe side of a fourth toe on an instep side to a region near a first toe side of the fifth toe on a volar side, the outer low-elasticity portion being less elastic than another part; an upper taping low-elasticity portion formed in a direction substantially toward an inner malleolus part side from a portion between an ankle and a base part of the fourth toe in the outer low-elasticity portion on the instep side, the upper taping low-elasticity portion being less elastic than another part; and an upper ankle low-elasticity portion formed in a circumferential direction in an upper ankle part and being less elastic than another part, wherein a shape of the sock from the toe tip part of the foot portion to the opening of the body portion is formed in substantially an arcuate shape such that an outer side of the sock is shorter than an inner side of the sock.
 2. The sock according to claim 1, further comprising: a lower taping low-elasticity portion formed in a direction substantially toward the inner malleolus part side from a region near a heel part side between a heel part and the base part of the fifth toe in the outer low-elasticity portion on a sole side, the lower taping low-elasticity portion being less elastic than another part.
 3. The sock according to claim 1, wherein the upper ankle low-elasticity portion is formed over substantially the entire circumference of the upper ankle part, and a part of the upper ankle low-elasticity portion in the circumferential direction is formed to be more elastic than a remaining part of the upper ankle low-elasticity portion. 